This invention relates to new acetylenic compositions and to the use of such compositions in plating baths for the electrodeposition of nickel and nickel-iron alloys.
Aqueous acidic plating baths for producing nickel coatings on substrates have been known in the art, and most nickel plating baths are based on the use of a standard Watts-type bath which includes nickel sulfate, nickel chloride and boric acid dissolved in water. Various additives have been incorporated into the Watts-type baths to improve the quality of the coatings.
Methods for producing nickel-iron alloys on substrates also have been described in the art, and similarly, most of the nickel-iron plating baths are based on the use of standard Watts-type baths to which has been added ferrous sulfate. Many additives also have been suggested as being useful in such nickel-iron plating baths, and the present invention relates to the discovery that the quality of the deposits derived from such nickel and nickel-iron plating baths can be improved by incorporating therein novel acetylenic compositions as described hereinafter.
Modern processes as described in the prior art relating to the use of the Watts-type bath are generally used in conjunction with additive systems which comprise brighteners known as Class I brighteners which include compositions such as bath-soluble sulfinic acids, sulfonic acids, sulfonamides, sulfonimides, sulfimides and the water-soluble salts of these materials. The plating baths also can and generally will contain Class II brighteners which generally are unsaturated organic materials which will produce the leveling and increase the luster of deposit when used in conjunction with the Class I brighteners. Typical Class II brighteners for nickel plating baths are acetylenic or ethylenic alcohols, ethoxylated and propoxylated acetylenic alcohols, coumarins, aldehydes, and compounds containing the C.tbd.N linkage.
The use of acetylenic compositions as brighteners for nickel and nickel-iron plating baths has gained wide acceptance and has been described in many patents. Various acetylenic-containing compositions have been suggested including acetylenic amines, acetylenic alcohols, acetylenic esters, acetylenic sulfonic acids and sulfonates and alkoxylated acetylenic alcohols and amines. Illustrative of the patents describing the use of acetylenic derivatives as brighteners in nickel and nickel-iron plating baths include the following U.S. Pat. Nos. 3,133,006; 3,140,988; 3,152,975; 3,160,574; 3,170,853; 3,305,462; 3,366,557; 3,699,016; 3,378,470; 3,502,550; 3,515,652; 3,711,384; 3,719,568; 3,723,260; 3,759,803; 3,795,592; 3,860,638; 3,862,019; 3,844,773; 3,898,138; 3,907,876; 3,969,198; 4,054,495; 4,062,738.